Method and means for locating lamps



Dec. 1, 19325- D. J. M CARTHY METHOD AND MEANS FOR LOCATING LAMPS FiledApril 28, 1921 Patented Dec. 1, 1925. H

ea @FFICE DANIEL J. MCCARTHY, OF ELGIN. ILLINOIS. ASSIGNOR TO CHICAGORAILWAY SIGNAL AND SUPPLY COMFANY, A CORPORATION OF ILLINOIS.

METHOD AND MEANS FOR LOCATING LAMPS.

Application filed. April 253, 1921. Serial No. 465,143.

To all whom it may concern:

Be it known that I, DANIEL J. NICGARTHY, a citizen of the United States,residing at Elgin, in the county of Kane and State of Illinois, haveinvented certain new and useful Improvements in Methods and Means forLocating Lamps, of which the following is a specification.

This invention relates to methods and means for locating lamps.

It will be explained as applied to a double lens signal lamp such as maybe used in railway work.

In many fields, such for example as railway signalling, electric signallamps often must be located in relatively inaccessible positions such asthe tops of poles. switches. signal towers, etc. The lamps burn out andotherwise become defective and must be replaced.

Not only is it important that the original lamp be properly positionedto give the desired results but replacements must give the same results.However the lamps and their 5 filaments vary in manufacture so that itimpossible to obtain uniform results try merely substituting new lampsfor old ones.

The position of the original. lamp may often be accurately fixed byordinary shop and laboratory photometric methods, but in the field suchmethods can not be followed and the apparatus necessitated thereby cannot be used.

One of the objects of this invention is to provide an improved method ofproperly locating lamps.

Another object is to provide a method and means which readily lendthemselves to field use.

Other objects and advantages will hereinafter appear.

An embodiment of apparatus whereby the improved method may be practicedis shown in the accompanying drawing.

The adjustable lamp support disclosed herein is claimed in my copendingapplica tion Serial No. 529,434, filed January 16, 1922.

The device for determining the position of the lamp is claimed in mycopending application Serial No. 429,433, filed January 16, 1922. i

The views in the drawings are as fol lows Fig. 1 is an elevation of arear view of a light unit showing the focus finder in place thereon.

Fig. 2 is a vertical section taken on line 22 of Fig. 1.

Fig. 3 is a view similar to Fig. 2, showing a fragment thereof.

Fig. 4 is an enlarged sectional view of a part of the lamp adjustingsupport, taken on line 4-4 of Fig. 2. i

Fig. 5 is a similar view to Fig. 4 taken on line 55 of 2.

Fig. 6 is a section of part of the focus finder taken on line 6-6 ofFig. 2.

Fig. 7 shows a view in side elevation of the conventional filament of anelectric lamp.

Fig. 8 is a diagran'i of the focus finder with the lamp displaced, onthe focal axis and forward of the focal point.

In all the views the same reference characters are employed to indicatesimilar parts.

To obtain the highest eiiiciency in the projection of light by lenses,reflectors. or the like. it is quite essential that the source oflight,.such as the filament of an electric lamp, be placed at the exactfocal point of the projector; when this has been achieved the light maybe made, by use of a proper arrangement of lenses. to produce a beam oflight in which the rays are in parallel lines, thus projecting a moreintense and far reaching beam of light. By moving the lamp along thefocal axis of the light projector towards the projector the rays may bemade to outwardly diverge or flare while if the lamp be moved out of thefocal point in the opposite direction the rays of light may thus be madeto converge.

In railway signal systems, in different situations, the signal lampunits are required to project beams of light in which the rays areparallel; in other locations the rays of light must be diverging so asto extend over a relatively large light field at the objective point,and in others the light beam must be more concentrated at the point ofapplication. For uniformity of appar-tus an economy of eqrupment, it ishighly desirable that a Slllfile structure be .uiadc cajmble, bv

proper ad stinent. to meet the various requirements of It is furthermorenecessary to be able to ascertain and to note the extent to which thefield of illumination is extended or contracted, that is, the measure indegrees of digression from a beam of parallel rays. The in strumentherein disclosed and the method of its operation is intended moreparticularly for readily establishing the filament of a new electriclamp in a lamp unit, in pre cisely the same location of the filament ofthe lamp initially installed in the unit, whereby it will produce thesame results as the latter. although it may vary in some of itsstructural features or other characteristics from the original lamp.

The drawings show portions of a more or less conventionalsignal lampunit in which it) is a part of the unit casing providing a ring 11 for alens 12, and a ring 13 for a lens 14. In this doublet arrangement orlenses, when the filament 15 of the electric lamp is located at theprecise focal point, as shown in Fig. 2, the rays of light projectedthere from will form a beam in which the rays will extend in parallellines. If the light point 15 be brought nearer to the smaller lens thelight beam will be more or less fan shape and if it be moved in theopposite di rection. the beam of light will be concentrated.

A means for moving the lamp and securing it in its desired position isaccomplished by the following instrnmentality at bracket 17 carries lampsockets 18 and 19, the lamp 16 is shown inserted in the lat ter, and isthe active lamp of the unit. The bracket is carried by or is part of atube or sleeve 20. which is threaded at one end. as at 21. i

A rotatable shaft carries at one end an eccentric 23 to which it isfixed thru the annular sleeve 23; at itsother end it is fixed to aneccentric 25 by a pin 26. These eccentrics form journals upon which theshaft is rotatably supported and while they are shown to be somewhatdifferent in diametric dimensions, the throw or eccentricity of the twoeccentrics is the same so that, upon rotation, the shaft 22 will bemoved in parallel. lines around the axisof its movement. The shaft andsleeve 23 are provided with a screw driver slot 27 for convenience ofrotation or they may be rotated bya wrench engaging the annular sleeve23. The eccentric is rotatable freely in a socket 28 Which is a fixedpart of. the frame 10. To retain theeccentric 25 in the socket it isprovided with a groove 29 into which a screw 30 projects from the socket28.

The eccentric 23 is rotatable in a ring 81 mascot which is part of arearwardly extending arm 32. which also carries the eccentric hearing orsocket 28. Arm 82 is bifurcated at its inner end prm'idiag supplementaryarms 33 and 34 fixed to the frame 10 by screws 7.

A tube or sleeve 36 overlies a large portion of shaft 22 and is freelyrotatable with respect thereto. It is provided with an axially parallelslot 87 into which a screw 38,

from the bracket sleeve 20. projects to permit the latter sleeve to beaxially moved thereon and to cause said sleeves 20 and 30 to be rotatedas one.

A nut 39, rotatable on the sleeve 2-36, is prevented froin being axiallymoved thereon by a screw 4L0, which extends therefrom into an annulargroove all in the sleeve. The sleeve 36 is normally held in fixedposition with respect to the frame 10 by a set screw 41 which passesthru a. hub d2 of sleeve 23. The screw ll is held in clamping positionby a nut 43. The sleeve 23 is fixed by a set screw slat which passesthru the hub 45 of ring 31, which is a part of the frame 10. A check nut4l6 securely holds the clamping set screw 44: in clamping position.

From the above description it will be manifest that the lamp 16 may bemoved to any desired point in a plane transverse to the focal axis ofthe lens combination by rotation of the shaft 22 and its connectedeccentrics and that itmay also be movedalong the focal axis by rotationof the nut 39 and fixed in its adjusted positions by the set screws 41and 44.

it the time when the light signal unit is assembled, alamp 16 is placedin the socket l9 and its filament energized. The filament is then placedapproximately at the focal point of the lens combination.

The beam of light from the outer lens is now measured photometrically.The lamp and filament are then movably adjusted and readings taken fromthe photometer until the exact focal point has been thus ascertained.whereupon the shiftable parts of the lamp adjusting device are locked infixed positions by the set screws. Of course. if it is desired to havethe signal unit project a flaring beam of determined degree the lamp andfilament are adjusted accordingly. Any suitable method and apparatus forphotometric calibration and measurement may be used.

After the lamp signal unit has been installed in service, it sometimeshappens that a new electric lamp must replace the original and thefilament of the new lamp must occupy the same position as that of theoriginal electric lamp.

The original shop method of finding the desired location or focal point,cannot be pursued for placing a new lamp because the unit is supportedon a pole or other inaccessible location and for this reason it isimpracticable or impossible to follow the original procedure outlinedabove. 1

I have therefore provided a focus finder and a method for reestablishingthe initial relation with a substitute electric lamp and its associatedlenses.

The instrument consists of a small closed casing 50 having anobservation aperture 51. A portion of its edge wall is iii-curved, as at52, the curved portion extending something more than 90 degrees andhaving portions of its wall inclined at .45 degrees from theperpendicular, as at 53 and 54. A small lens 55 is secured in an openingin the curved portion 52 of the housing Wall vertically above thefilament 15 and another similar lens 56 is located in an opening in saidcurved wall just 90 degrees removed. A light reflector 57 is secured tothe wall 54:, inclined just 45 degrees from the focal axis of the lens55. A similar mirror or reflector 58 is fixed in the same manner to theinclined wall 53 and inclined 45 degrees from the focal axis of the lens56 so that the beams of light reflected from the mirrors or reflectors57 and 58 will be in planes precisely 90 degrees in angular relation toeach other.

A plate of ground glass 59 is placed in the path of the beam 60, ofreflected light and located at right angles thereto, upon which toreceive the image 15 of the lamp filament 15.

A plate of ground glass 61 is placed in the path of the beam 62 ofreflected light from the lens 56 and located at right angles thereto,upon which to receive the image 15 of the lamp filament 15.

A reflector 62' is placed over the plate 61 and inclined substantially45 degrees so that an observer looking thru the aperture 51 will see thetwo reflected images 15 and 15 as they appear in Fig. 1, when the lampfilament 15 is in the position occupied by the original lamp which isthe focal point of the lens combination.

The plates 59 and 61 each have a longitudinally extending central line63 which blend into the line 63 as they appear to the observer inFig. 1. They each have a transversely extending line 64 and 65,respectively. When the images 15 and 15 are symmetrical with respect tothe associated transverse lines and with respect to the single verticalline 63 as shown. the former relations of the light point of the lampand lenses have been reestablished and the signal unit will operate withthe new lamp in the manner as before its original lamp became defective.

Should adjustment be required to produce divergence of light rays of 5degrees, 10 degrees or 15 degrees as exigencies of the case may require,at the field of illumination, means are provided for accuratelyascertaining the degree to which the light beam will be laterallyextended.

Fig. 8 shows the filament 15 moved toward the lens on the focal axis sothat the angle ofthe light beam is raised above the line 65, in a mannerclearly apparent, in which event the image 15" will be raised to theshort lines 5, 10 or 15, according to the degree of beam expansion, onthe plate 59, shown more clearly in Fig. 2-indicative of the respectivedegrees to which the light beam has been spread by the forward movementof the lamp 16.

Since. in the above example, the lamp is moved along the focal axis ofthe lens. there will be no disturbance of the light projected thrn lens56; therefore the image 15 will remain on cross line 64:.

To adjust the instrument 50 to a lamp signal unit in which the electriclamp has been located, in the manner heretofore described, so that itmay be removed and subsequently replaced with accuracy, the casing 50has projecting forwardly therefrom a tapered stem 66, having atransverse notch 67 in its smaller free end. At approximately the properposition in the frame 10 a socket 68 is made, which is considerablylarger than stem 66. A sleeve 69, the bore of which is tapered to neatlyfit the stem 66, has one or more grooves 70 and a transverse pin 71which the transverse notch 67 of the stem engages to prevent rotation ofthe stem and attached instrument.

hen the filament 15 has been properly located by adjustment of theinstrument the latter is fixed and temporarily held, with the stem 66and sleeve 69 in the socket 68, and with the image 15 and 15', as shownin Fig. 1. Then metal such as Babbitt metal, Zinc or lead, 72, is pouredinto the socket and around the sleeve 69 to hold the latter in place inthe socket. The instrument will now visually show the true focal pointof the lens, and may be removed and reinserted for subsequent use.

The instrument may advantageously be used in connection with a parabolicreflector, or other reflector.

While I have herein shown and described a single embodiment of theinvention for the purpose of a clear disclosure, it is manifest thatmany changes may be made in the configuration and disposition of theparts within the scope of the appended claims.

Having described my invention what I claim as new and desire to secureby Letters Patent. is

1. The method of locating a lamp filament at an objective point whichconsists in illuminating the filament; projecting two beams of lighttherefrom at substantially right angles to each other; reflecting bothof the beams towards each other; providing a receptive surface, one foreach beam upon near Where the :1 105 (1208191 pm impinge and 3151- M H M31m: the fihnmflv thrn each lens '0 '1 p fur 'pwsibio'n untilzsaidz-vfloctm' (m0 '2'01' each beam; reflecting both JQEU' :2prtdete'r'n'lined obsewing, toward each other to two re- W wentsur/fflcos. 3 sm'fiurei 21d adjust? the lump 1 mg: lump filament p08(E01 until fie hams app 1 new (be hm J OPt P-TQ point \vhi h (OHSiStS inm- 7 rsitahsawd 0n mid r-m'cp beams mi: 1: justive gwiiiu 00511 m'e imal winch are in. 0s from each Int z-zmp Hamel? in iname.

309 1111 a 119mm DJQUEL J. MVUARTUY.

